As natural gas began to be distributed via pipelines throughout the United States, agencies were variously developed to regulate the specifications of the natural gas that might be transported via pipeline. As experience with pipeline transportation grew, such standards were variously refined, and today in the United States, it is generally accepted that pipeline quality natural gas should not have a BTU content greater than about 1,050 BTUs per standard cubic foot (scf). It is felt that higher BTU contents can cause considerable operational problems and potential equipment damage to pipelines and pipeline step-up compressors, and to end users.
The increase in worldwide natural gas production has resulted in drilling and bringing on stream many gas fields that have a BTU content well above such desired maximum level. Thus, it has become important to be able to treat such streams so as to efficiently and economically reduce the BTU content to the maximum permitted. Although large NG production facilities may have liquefaction equipment available that is suitable for removal of these NGLs, thus far it has not been economical to duplicate such facilities on a much smaller level. Economical and efficient solutions to this problem have been sought for a number of years. In addition, air pollution from oil production flares has become a significant problem as a result of increases in oil production and refining.